Well, the latest study extolling the evils of saturated fat has hit the ground running. You may have caught some of the headlines: "One High-Saturated Fat Meal Can Be Bad", Washington Post; "Just one high-saturated fat meal bad for arteries, study says", Globe & Mail. The abstract of the study can be found here,http://content.onlinejacc.org/cgi/content/abstract/48/4/715, but allow me to sum it up for you. It's just a super awesome study, as so many of the evil sat-fat studies are.
The study was published in the Journal of the American College of Cardiology, and set out to examine the arterial effects of a saturated fat meal vs. a polyunsaturated fat meal. Sounds fun! Lead researcher Dr. Stephen Nicholls (trust me- I'm a doctor) and his colleagues at the Heart Research Institute in Sydney, Australia (trust me- I'm an institute) observed a whopping fourteen men aged 18-40 after they had eaten a meal containing either saturated fat (from coconut oil) or polyunsaturated fat (from safflower oil). The men all had healthy BMI (body mass index) readings and had fasted overnight prior to consuming the meal. The men were given each meal a month apart. Sounds great so far!
Here's what the study found, according to media reports: eating just one meal high in saturated fat can prevent "good" cholesterol from protecting the body from clogged arteries. Researchers discovered that found that three hours after eating the sat-fat meal, the lining of the arteries was hindered from expanding to increase blood flow. And after six hours, the anti-inflammatory qualities of the good cholesterol were reduced. The polyunsaturated meal, on the other hand, seemed to improve those anti-inflammatory qualities. Also, fewer inflammatory agents were found in the arteries than before the meal. Wowza!
Before you stock up on safflower oil, let's ask a quick question. What were these meals made up of? I mean, these people (all fourteen of them) weren't just eating bowlfuls of oil, were they? Of course they weren't! They were given a perfectly reasonable meal, one that would ensure that no other nutritional variables besides fat could possibly influence the outcome:
Carrot cake and a milkshake. 1426 calories. No ingredient or nutritional breakdown, other than a 70g fat count for each meal. Also no word on whether the shake was chocolate or vanilla (I'm a strawberry gal myself), how thick it was, or if any of the participants at any time fell victim to the dreaded "ice-cream headache".
Now, I'm no scientist (trust me - I'm not a scientist) but even I can see that a meal full of carbs and SUGAR may have an effect as well. But just for kicks, let's see what actually came out of this study. I credit Dr. Michael Eades (okay...I actually trust him) with the following, which you can find in his blog athttp://www.proteinpower.com/drmike/archives/2006/08/saturated_fat_s.html
The researchers looked at four different parameters. They wanted to see if the difference in fat type made a difference in blood lipid and insulin levels, if it made a difference in the way the subjects arteries reacted in a couple of different ways, and they wanted to see if the different fats made the HDL particles less anti-inflammatory.
First, looking at the difference between serum total cholesterol, LDL, HDL, triglycerides, Insulin, and non-esterified fatty acid levels after the two diets, we find that only two--total cholesterol levels and LDL levels--are different to a statistically significant degree. Both were lower after the saturated fat meal. Now most low-fat advocates believe that LDL is the single most important lipid parameter in existence, but for some reason these guys chose to not even mention the fact that in this study LDL was lower on the saturated fat diet than on the polyunsaturated fat diet. I wonder why?
Next, the researchers performed two different tests for evaluating arterial function on the subjects. One of these tests was a measurement of forearm blood flow; the other was a measurement of brachial artery (a large artery in the arm) diameter change. Both of these methods of evaluation are difficult to explain using non-technical language, but basically both work in similar ways. When blood vessels are compressed with a tourniquet for a period of time, the arteries downstream from the area of restriction receive little to no blood. When the tourniquet is released, blow flows into the artery and the artery dilates. You can press your thumb hard into the inside of your forearm and hold it for 10 seconds. When you remove your thumb, the area underneath will be white. As you watch, the area under your thumb print will become pinkish red as blood flows back into it. The more quickly blood flows back in, the better your arterial and capillary function. The two tests used in this study look at this same thing only using much more sophisticated techniques.
In one of the two tests there was a slight difference in the negative direction at the 3 hour mark with the saturated fat diet, but overall there was no statistically significant difference between the two diets in either test.
Visit Dr. Mike's blog for the full breakdown. Now, here are the conclusions of the study, found at the end of the paper:
In summary, the present study raises the possibility that the differential effects of dietary fats on the anti-inflammatory potential of HDL and endothelial function may contribute to the apparent benefits of polyunsaturated over saturated diets observed in the epidemiologic literature.
Pretty different than "One meal of saturated fat may harm you". Basically, it showed that if you're eating a diet full of sugar and processed carbs, you may be slightly better off with polyunsaturated fats in your baked goods. Um, whoopie.
Media and many nutritionists still love to demonize sat-fat, even though it has been vindicated as a horseman of arterial apocalypse. Still afraid of animal fat? Visit the following:
http://www.westonaprice.org/knowyourfats/import_sat_fat.html
http://www.westonaprice.org/knowyourfats/skinny.html
http://www.lowcarbportal.com/archives/2004/11/09/more_saturated_fat_less_coronar
http://www.webmd.com/content/article/98/104684.htm?src=rss_cbsnews
And the next time you read a health-news headline, take it with a grain of salt. And a pat of butter.
Note: The study was funded, through their Young Investigator Award, by Pfizer. Ahem. Lipitor, anyone?
(Thanks to Dr. Eades and Jimmy Moore athttp://livinlavidalocarb.blogspot.com/for their much better information!)
Well, the latest study extolling the evils of saturated fat has hit the ground running. You may have caught some of the headlines: "One High-Saturated Fat Meal Can Be Bad", Washington Post; "Just one high-saturated fat meal bad for arteries, study says", Globe & Mail. The abstract of the study can be found here,http://content.onlinejacc.org/cgi/content/abstract/48/4/715, but allow me to sum it up for you. It's just a super awesome study, as so many of the evil sat-fat studies are.
The study was published in the Journal of the American College of Cardiology, and set out to examine the arterial effects of a saturated fat meal vs. a polyunsaturated fat meal. Sounds fun! Lead researcher Dr. Stephen Nicholls (trust me- I'm a doctor) and his colleagues at the Heart Research Institute in Sydney, Australia (trust me- I'm an institute) observed a whopping fourteen men aged 18-40 after they had eaten a meal containing either saturated fat (from coconut oil) or polyunsaturated fat (from safflower oil). The men all had healthy BMI (body mass index) readings and had fasted overnight prior to consuming the meal. The men were given each meal a month apart. Sounds great so far!
Here's what the study found, according to media reports: eating just one meal high in saturated fat can prevent "good" cholesterol from protecting the body from clogged arteries. Researchers discovered that found that three hours after eating the sat-fat meal, the lining of the arteries was hindered from expanding to increase blood flow. And after six hours, the anti-inflammatory qualities of the good cholesterol were reduced. The polyunsaturated meal, on the other hand, seemed to improve those anti-inflammatory qualities. Also, fewer inflammatory agents were found in the arteries than before the meal. Wowza!
Before you stock up on safflower oil, let's ask a quick question. What were these meals made up of? I mean, these people (all fourteen of them) weren't just eating bowlfuls of oil, were they? Of course they weren't! They were given a perfectly reasonable meal, one that would ensure that no other nutritional variables besides fat could possibly influence the outcome:
Carrot cake and a milkshake. 1426 calories. No ingredient or nutritional breakdown, other than a 70g fat count for each meal. Also no word on whether the shake was chocolate or vanilla (I'm a strawberry gal myself), how thick it was, or if any of the participants at any time fell victim to the dreaded "ice-cream headache".
Now, I'm no scientist (trust me - I'm not a scientist) but even I can see that a meal full of carbs and SUGAR may have an effect as well. But just for kicks, let's see what actually came out of this study. I credit Dr. Michael Eades (okay...I actually trust him) with the following, which you can find in his blog athttp://www.proteinpower.com/drmike/archives/2006/08/saturated_fat_s.html
The researchers looked at four different parameters. They wanted to see if the difference in fat type made a difference in blood lipid and insulin levels, if it made a difference in the way the subjects arteries reacted in a couple of different ways, and they wanted to see if the different fats made the HDL particles less anti-inflammatory.
First, looking at the difference between serum total cholesterol, LDL, HDL, triglycerides, Insulin, and non-esterified fatty acid levels after the two diets, we find that only two--total cholesterol levels and LDL levels--are different to a statistically significant degree. Both were lower after the saturated fat meal. Now most low-fat advocates believe that LDL is the single most important lipid parameter in existence, but for some reason these guys chose to not even mention the fact that in this study LDL was lower on the saturated fat diet than on the polyunsaturated fat diet. I wonder why?
Next, the researchers performed two different tests for evaluating arterial function on the subjects. One of these tests was a measurement of forearm blood flow; the other was a measurement of brachial artery (a large artery in the arm) diameter change. Both of these methods of evaluation are difficult to explain using non-technical language, but basically both work in similar ways. When blood vessels are compressed with a tourniquet for a period of time, the arteries downstream from the area of restriction receive little to no blood. When the tourniquet is released, blow flows into the artery and the artery dilates. You can press your thumb hard into the inside of your forearm and hold it for 10 seconds. When you remove your thumb, the area underneath will be white. As you watch, the area under your thumb print will become pinkish red as blood flows back into it. The more quickly blood flows back in, the better your arterial and capillary function. The two tests used in this study look at this same thing only using much more sophisticated techniques.
In one of the two tests there was a slight difference in the negative direction at the 3 hour mark with the saturated fat diet, but overall there was no statistically significant difference between the two diets in either test.
Visit Dr. Mike's blog for the full breakdown. Now, here are the conclusions of the study, found at the end of the paper:
In summary, the present study raises the possibility that the differential effects of dietary fats on the anti-inflammatory potential of HDL and endothelial function may contribute to the apparent benefits of polyunsaturated over saturated diets observed in the epidemiologic literature.
Pretty different than "One meal of saturated fat may harm you". Basically, it showed that if you're eating a diet full of sugar and processed carbs, you may be slightly better off with polyunsaturated fats in your baked goods. Um, whoopie.
Media and many nutritionists still love to demonize sat-fat, even though it has been vindicated as a horseman of arterial apocalypse. Still afraid of animal fat? Visit the following:
http://www.westonaprice.org/knowyourfats/import_sat_fat.html
http://www.westonaprice.org/knowyourfats/skinny.html
http://www.lowcarbportal.com/archives/2004/11/09/more_saturated_fat_less_coronar
http://www.webmd.com/content/article/98/104684.htm?src=rss_cbsnews
And the next time you read a health-news headline, take it with a grain of salt. And a pat of butter.
Note: The study was funded, through their Young Investigator Award, by Pfizer. Ahem. Lipitor, anyone?
(Thanks to Dr. Eades and Jimmy Moore athttp://livinlavidalocarb.blogspot.com/for their much better information!)